Smart beta has a broad meaning, but we can say in practice that when we use the universe of stocks from an index, and then apply some weighting scheme other than market cap weighting, it can be considered a type of smart beta fund. A Smart Beta portfolio generally gives investors exposure or "beta" to one or more types of market characteristics (or factors) that are believed to predict prices while giving investors a diversified broad exposure to a particular market. Smart Beta portfolios generally target momentum, earnings quality, low volatility, and dividends or some combination. Smart Beta Portfolios are generally rebalanced infrequently and follow relatively simple rules or algorithms that are passively managed. Model changes to these types of funds are also rare requiring prospectus filings with US Security and Exchange Commission in the case of US focused mutual funds or ETFs.. Smart Beta portfolios are generally long-only, they do not short stocks.
In contrast, a purely alpha-focused quantitative fund may use multiple models or algorithms to create a portfolio. The portfolio manager retains discretion in upgrading or changing the types of models and how often to rebalance the portfolio in attempt to maximize performance in comparison to a stock benchmark. Managers may have discretion to short stocks in portfolios.
Imagine you're a portfolio manager, and wish to try out some different portfolio weighting methods.
One way to design portfolio is to look at certain accounting measures (fundamentals) that, based on past trends, indicate stocks that produce better results.
For instance, you may start with a hypothesis that dividend-issuing stocks tend to perform better than stocks that do not. This may not always be true of all companies; for instance, Apple does not issue dividends, but has had good historical performance. The hypothesis about dividend-paying stocks may go something like this:
Companies that regularly issue dividends may also be more prudent in allocating their available cash, and may indicate that they are more conscious of prioritizing shareholder interests. For example, a CEO may decide to reinvest cash into pet projects that produce low returns. Or, the CEO may do some analysis, identify that reinvesting within the company produces lower returns compared to a diversified portfolio, and so decide that shareholders would be better served if they were given the cash (in the form of dividends). So according to this hypothesis, dividends may be both a proxy for how the company is doing (in terms of earnings and cash flow), but also a signal that the company acts in the best interest of its shareholders. Of course, it's important to test whether this works in practice.
You may also have another hypothesis, with which you wish to design a portfolio that can then be made into an ETF. You may find that investors may wish to invest in passive beta funds, but wish to have less risk exposure (less volatility) in their investments. The goal of having a low volatility fund that still produces returns similar to an index may be appealing to investors who have a shorter investment time horizon, and so are more risk averse.
So the objective of your proposed portfolio is to design a portfolio that closely tracks an index, while also minimizing the portfolio variance. Also, if this portfolio can match the returns of the index with less volatility, then it has a higher risk-adjusted return (same return, lower volatility).
Smart Beta ETFs can be designed with both of these two general methods (among others): alternative weighting and minimum volatility ETF.
Each problem consists of a function to implement and instructions on how to implement the function. The parts of the function that need to be implemented are marked with a # TODO comment. After implementing the function, run the cell to test it against the unit tests we've provided. For each problem, we provide one or more unit tests from our project_tests package. These unit tests won't tell you if your answer is correct, but will warn you of any major errors. Your code will be checked for the correct solution when you submit it to Udacity.
When you implement the functions, you'll only need to you use the packages you've used in the classroom, like Pandas and Numpy. These packages will be imported for you. We recommend you don't add any import statements, otherwise the grader might not be able to run your code.
The other packages that we're importing are helper, project_helper, and project_tests. These are custom packages built to help you solve the problems. The helper and project_helper module contains utility functions and graph functions. The project_tests contains the unit tests for all the problems.
import sys
!{sys.executable} -m pip install -r requirements.txt
import pandas as pd
import numpy as np
import helper
import project_helper
import project_tests
df = pd.read_csv('../../data/project_3/eod-quotemedia.csv')
percent_top_dollar = 0.2
high_volume_symbols = project_helper.large_dollar_volume_stocks(df, 'adj_close', 'adj_volume', percent_top_dollar)
df = df[df['ticker'].isin(high_volume_symbols)]
close = df.reset_index().pivot(index='date', columns='ticker', values='adj_close')
volume = df.reset_index().pivot(index='date', columns='ticker', values='adj_volume')
dividends = df.reset_index().pivot(index='date', columns='ticker', values='dividends')
To see what one of these 2-d matrices looks like, let's take a look at the closing prices matrix.
project_helper.print_dataframe(close)
In Part 1 of this project, you'll build a portfolio using dividend yield to choose the portfolio weights. A portfolio such as this could be incorporated into a smart beta ETF. You'll compare this portfolio to a market cap weighted index to see how well it performs.
Note that in practice, you'll probably get the index weights from a data vendor (such as companies that create indices, like MSCI, FTSE, Standard and Poor's), but for this exercise we will simulate a market cap weighted index.
The index we'll be using is based on large dollar volume stocks. Implement generate_dollar_volume_weights to generate the weights for this index. For each date, generate the weights based on dollar volume traded for that date. For example, assume the following is close prices and volume data:
Prices
A B ...
2013-07-08 2 2 ...
2013-07-09 5 6 ...
2013-07-10 1 2 ...
2013-07-11 6 5 ...
... ... ... ...
Volume
A B ...
2013-07-08 100 340 ...
2013-07-09 240 220 ...
2013-07-10 120 500 ...
2013-07-11 10 100 ...
... ... ... ...The weights created from the function generate_dollar_volume_weights should be the following:
A B ...
2013-07-08 0.126.. 0.194.. ...
2013-07-09 0.759.. 0.377.. ...
2013-07-10 0.075.. 0.285.. ...
2013-07-11 0.037.. 0.142.. ...
... ... ... ...def generate_dollar_volume_weights(close, volume):
"""
Generate dollar volume weights.
Parameters
----------
close : DataFrame
Close price for each ticker and date
volume : str
Volume for each ticker and date
Returns
-------
dollar_volume_weights : DataFrame
The dollar volume weights for each ticker and date
"""
assert close.index.equals(volume.index)
assert close.columns.equals(volume.columns)
#TODO: Implement function
dollar_volume_weights = pd.DataFrame(index=close.index, columns=close.columns).astype('float')
total_daily_volume = np.sum(close * volume, axis=1)
dollar_volume = close * volume
print(dollar_volume)
print()
print(total_daily_volume)
for index, col in total_daily_volume.iteritems():
dollar_volume_weights.loc[index] = dollar_volume.loc[index] / col
print(dollar_volume_weights)
return dollar_volume_weights
project_tests.test_generate_dollar_volume_weights(generate_dollar_volume_weights)
Let's generate the index weights using generate_dollar_volume_weights and view them using a heatmap.
index_weights = generate_dollar_volume_weights(close, volume)
project_helper.plot_weights(index_weights, 'Index Weights')